1. Technical Field
The present invention relates to a cleaning mechanism for removing ink from a transportation roller that is positioned to contact the printing surface of the recording medium, and to a printer having this cleaning mechanism.
2. Related Art
Some printers that print by ejecting ink onto a recording medium have transportation rollers disposed downstream from the printhead to grip the printed recording medium from both sides and convey the recording medium toward a paper exit. Because one of the rollers in this transportation roller pair contacts the printed side of the recording medium, undried ink may be picked up by the roller surface. Ink accumulated on the roller surface can then transfer to the recording medium and soil the printed surface. Some devices therefore suppress ink buildup and retransfer to another surface by forming grooves in the roller surface. A cleaning member could also be provided to remove any ink and clean the roller surface.
Japanese Unexamined Patent Appl. Pub. JP-A-H06-182983 teaches a printer that uses grooved spurs as the roller that contacts the printing surface. This printer also has a cleaning roller that rotates in constant contact with the spurs and removes ink at the same time as the spurs rotate. The position of the spurs is also automatically adjusted according to the thickness of the recording medium in this printer, and when the spurs move, the cleaning roller also moves following the spurs. The cleaning roller therefore does not interfere with retracting the spurs, and can clean the spurs without affecting paper feed performance.
Japan Patent No. 4407566 teaches a printer that has a cleaning member disposed at the front of the tray used to load a CD, DVD, or other recording medium into the printer. When the tray is inserted in this printer, the discharge follower roller on which there is ink contacts the cleaning member, and the ink is removed from the roller. Because cleaning occurs when the tray is loaded and unloaded with this configuration, cleaning can be performed without affecting transportation performance. In addition, because the cleaning member is on the tray side, the removed ink is discharged with the tray from the printer.
A problem with the related art taught in JP-A-H06-182983 is that because the cleaning roller is in constant contact with the spurs while the spurs (transportation roller) rotate, cleaning continues constantly while the recording medium is conveyed, and the ink removed from the spurs builds up on the cleaning roller while the recording medium is conveyed. However, JP-A-H06-182983 is silent about how to remove accumulated ink from the cleaning roller, and ink on the cleaning roller can transfer back onto the spurs while conveying the recording medium and soil the printing surface.
With the printer taught in Japan Patent No. 4407566, cleaning does not occur unless printing on a CD, DVD, or similar recording medium because cleaning occurs only when the tray moves in and out. Cleaning may therefore not occur as frequently as needed when the user uses a printer such as taught in Japan Patent No. 4407566 but does not print on recording media such as CDs or DVDs.